In recent years, with the rapid development of technology, cases where one user has two or more electronic device in his/her name have been on an increasing trend. Examples of the electronic devices that have been most widely spread are mobile phones, smartphones, etc., performing communication. Recently, a variety of electronic devices that may be used with smartphones have been released on the markets, e.g., smart watches, smart glasses, tablet computers, etc., which are equipped with a communication function. In addition, systems for controlling a variety of electronic devices at home by using smart phones have been developed. For example, systems have been developed to control various electronic devices, e.g., a TV, washing machine, refrigerator, micro-oven, gas stove, electric heater, lights, etc., by a specific electronic device such as a smart phone.
A variety of electronic devices that users may usually carry have been developed, for example: a smart watch with a voice communication function; smart glasses with a communication function, a tablet computer; users' vital signal monitoring systems such as an electronic heart rate measuring device, a body temperature measuring device, a blood pressure measuring device; etc.
When one user carries two or more electronic devices or lives with the devices worn on his/her body, a case where all the devices need to perform the same operation may occur. In that case, the user may have difficulty in controlling functions of the devices or altering in the mode or settings of the devices, respectively.